In a brake mechanism of this type, which is known from German Offenlegungsschrift No. 2,217,707, one end of the prestressed brake spring engages with the brake band on the rocker arm which has a single-arm configuration. In the release position of the brake band, this rocker arm with tensioned brake spring is stopped by a stop pawl which is under the tension of a torsion spring. For the purpose of unlocking the stop pawl, a pin which is located excentrically with respect to the rotational axis of the hand protection lever is provided. The pin lifts the stop pawl out of a detent on the lever arm which is connected with the brake band and the brake spring, during the release motion of the hand protection lever, whereby the brake spring is released and the braking process is initiated by the application of the brake band on the brake drum. For the purpose of tensioning the brake spring, a second, also excentrically located pin is connected with the hand protection lever. This pin, upon a rotating motion of the hand protection lever in the direction away from the guide handle, pushes the rocker arm away (with a simultaneous tensioning of the brake spring) to such an extent that the stop pawl can seat in its stop position. This known braking device requires a relatively large consturctional outlay, together with a correspondingly high space requirement for accommodating the braking mechanism in the housing of the saw.